s=input()
s1=""
for char in s:
    if char =='(':
        s1+=char
    if char ==')':
        if len(s1)>0:
            if s1[len(s1)-1]=='(':
                s1=s1[:-1]
if len(s1)==0:
    print('true')
if len(s1)!=0:
    print('false')
